1. Field of the Invention
This invention relates to a device for accelerating, and thereby imparting velocity and momentum to a fluid, especially to air, through the use of ions and electrical fields.
2. Description of the Related Art
A number of patents (see, e.g., U.S. Pat. Nos. 4,210,847 and 4,231,766) have recognized the fact that ions may be generated by an electrode (termed the “corona electrode”), attracted (and, therefore, accelerated) toward another electrode (termed the “attracting electrode”), and impart momentum, directed toward the attracting electrode, to surrounding air molecules through collisions with such molecules.
The corona electrode must either have a sharp edge or be small in size, such as a thin wire, in order to create a corona discharge and thereby produce in the surrounding air ions of the air molecules. Such ions have the same electrical polarity as does the corona electrode.
Any other configuration of corona electrodes and other electrodes where the potential differences between the electrodes are such that ion-generating corona discharge occurs at the corona electrodes may be used for ion generation and consequent fluid acceleration.
When the ions collide with other air molecules, not only do such ions impart momentum to such air molecules, but the ions also transfer some of their excess electric charge to these other air molecules, thereby creating additional molecules that are attracted toward the attracting electrode. These combined effects cause the so-called electric wind.
However, because a small number of ions are generated by the corona electrode in comparison to the number of air molecules which are in the vicinity of the corona electrode, the ions in the present electric wind generators must be given initial high velocities in order to move the surrounding air. To date, even these high initial ionic velocities have not produced significant speeds of air movement. And, even worse, such high ionic velocities cause such excitation of surrounding air molecules that substantial quantities of ozone and nitrogen oxides, all of which have well-known detrimental environmental effects, are produced.
Presently, no invention has even attained significant speeds of air movement, let alone doing so without generating undesirable quantities of ozone and nitrogen oxides.
Three patents, viz., U.S. Pat. Nos. 3,638,058; 4,380,720; and 5,077,500, have, however, employed on a rudimentary level some of the techniques which have enabled the present inventors to achieve significant speeds of air movement and to do so without generating undesirable quantities of ozone and nitrogen oxides.
U.S. Pat. No. 5,077,500, in order to ensure that all corona electrodes “work under mutually the same conditions and will thus all engender mutually the same corona discharge,” uses other electrodes to shield the corona electrodes from the walls of the duct (in which the device of that patent is to be installed) and from other corona electrodes. These other electrodes, according to lines 59 through 60 in column 3 of the patent, “ . . . will not take up any corona current . . . .”
Also, U.S. Pat. No. 4,380,720 employs multiple stages, each consisting of pairs of a corona electrode and an attracting electrode, so that the air molecules which have been accelerated to a given speed by one stage will be further accelerated to an even greater speed by the subsequent stage. U.S. Pat. No. 4,380,720 does not, however, recognize the need to neutralize substantially all ions and other electrically charged particles, such as dust, prior to their approaching the corona electrode of the subsequent stage in order to avoid having such ions and particles repelled by that corona electrode in an upstream direction, i.e., the direction opposite to the velocity produced by the attracting electrode of the previous stage.
And U.S. Pat. No. 5,077,500, on lines 25 through 29 of column 1, states, “The air ions migrate rapidly from the corona electrode to the target electrode, under the influence of the electric field, and relinquish their electric charge to the target electrode and return to electrically neutral air molecules.” The fact that the target electrode is not, however, so effective as to neutralize substantially all of the air ions is apparent from the discussion of ion current between the corona electrode K and the surfaces 4, which discussion is located on lines 15 through 27 in column 4.
Similarly, U.S. Pat. No. 3,638,058 provides, on line 66 of column 1 through line 13 of column 2, “ . . . it can be seen that with a high DC voltage impressed between cathode point 12 and ring anode 18, an electrostatic field will result causing a corona discharge region surrounding point 14. This corona discharge region will ionize the air molecules in proximity to point 14 which, being charged particles of the same polarity as the cathode, will, in turn, be attracted toward ring anode 18 which will also act as a focusing anode. The accelerated ions will impart kinetic energy to neutral air molecules by repeated collisions and attachment. Neutral air molecules thus accelerated, constitute the useful mechanical output of the ion wind generator. The majority of ions, however, will end their usefulness upon reaching the ring 18 where they fan out radially and collide with the ring producing anode current. A small portion of the ions will possess sufficient kinetic energy to continue on through the ring along with the neutral particles. These result in a slight loss of efficiency because they tend to be drawn back to the anode. The same theory will apply for cathode 13 and anode 17. Since opposite polarities are impressed on each cathode-anode pair, their exiting airstreams will contain oppositely charged ions which will merge and neutralize; i.e., being of opposite polarity, the ions will attract each other and be neutralized by recombination. “It is, however, not clear that substantially all ions which escape the electrodes will merge because many ions emerging from the anode on the left are likely to have such momentum toward the left that the electrical attraction for ions emerging from the anode on the right with momentum toward the right is insufficent to overcome such opposite momenta. Furthermore, the distance required for such recombination as does occur is very probably so great that it would be a detriment to using multiple stages to provide increased speed to the air.